Urethane adhesives are used for bonding various substrates together such as automotive fiberglass reinforced parts.
U.S. Pat. No. 4,876,308 to Melby relates to a two-component type primerless polyurethane adhesive which has a high ratio of free NCO groups in the prepolymer component to the hydroxy groups and amine groups in the curative component of at least 1.2.
U.S. Pat. No. 4,923,756 to Chung et al relates to a laminated fiberglass reinforced polyester substrate made utilizing a primerless adhesive made from a first part which is a blend of a prepolymer component and an aliphatic isocyanate and a second component which is a curative. The prepolymer is the reaction product of a polyol and an aromatic isocyanate with a prepolymer product having from 3 to 15 percent of free isocyanate groups therein.